Slip Effect of Nanobubbles under the Influence of Hydrophilic and Hydrophobic Structures in Asymmetric Channels

被引：0
|
作者：
Dai S.-W. [1 ,2 ]
Lu Y. [1 ,2 ]
Gao Y.-M. [1 ,2 ]
Li Y.-F. [1 ,2 ]
机构：
[1] Key Laboratory of Metallurgical Equipment and Control Technology of Ministry of Education, Wuhan University of Science and Technology, Wuhan
[2] Key Laboratory of Mechanical Transmission and Manufacturing Engineering, Wuhan University of Science and Technology, Wuhan
来源：
Surface Technology | 2022年 / 51卷 / 02期
基金：
中国国家自然科学基金;
关键词：
microchannel; nanobubbles; slip drag reduction; temperature step; velocity slip; wettability;
D O I：
10.16490/j.cnki.issn.1001-3660.2022.02.019
中图分类号：
学科分类号：
摘要：
The purpose of this paper is to achieve a good fluid drag reduction effect by studying the relationship between the characteristics of nanobubbles and boundary slip under the influence of hydrophilic and hydrophobic surface structures in asymmetric channels. In this paper, the binary system molecular dynamics method is used to study the slip drag reduction effect of nanobubbles flowing in the channel. Firstly, the asymmetric microchannel model on the upper and lower walls is established, and the microchannel interface velocity slip phenomenon under the influence of nanobubbles is explored by considering the flow and heat transfer process of the microchannel. The simulation results show that when keeping the height of the hydrophilic lower wall and the temperature difference between the upper and lower walls unchanged, the increase in the height of the nanostructures on the upper wall promotes the volume increase of nanobubbles in the channel; in addition, when the upper wall is a hydrophobic wall, the nanobubbles appear in the form of a wall surface. As the volume increases, the slip length of the upper wall in the corresponding channel increases; when the upper wall is a hydrophilic wall, the nanobubbles are in bulk form, and as the volume increases, the corresponding upper wall’s slip length is reduced. In an asymmetrical channel, under the influence of the height of the upper wall structure, the increase of the nanobubble volume in the form of a wall surface promotes the drag reduction in the channel, while the increase of the nanobubble volume in the bulk form inhibits the drag reduction in the channel. Therefore, the research results in this paper provide a theoretical basis for exploring the application of nanobubble engineering in drag reduction. © 2022, Chongqing Wujiu Periodicals Press. All rights reserved.
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页码：202 / 210
页数：8
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